Thus there is provided a method of installing rotor blades of a wind turbine to a rotor hub of the wind turbine. The wind turbine has a tower having a tower longitudinal axis. The rotor hub has a first, a second and a third rotor blade connection. The rotor hub is rotated until the first rotor blade connection is at an angle of 90° or 270° with respect to the tower longitudinal axis. The first rotor blade is lifted substantially horizontally and fixed to the rotor blade connection. The rotor hub is rotated so that the second rotor blade connection is at an angle of 90° or 270° with respect to the tower longitudinal axis. The second rotor blade is lifted substantially horizontally and fixed to the second rotor blade connection. The rotor hub is further rotated until the third rotor blade connection is at an angle of 60° or 300° with respect to the tower longitudinal axis. The third rotor blade is lifted at an angle of α=30° with respect to a horizontal and fixed to the third rotor blade connection.